1. Field of the Invention
The present invention relates, in general, to hinges and, more specifically, to vehicle closure panel hinges.
2. Background Description
Automotive vehicles have one or more deck lids, such as a trunk lid, which typically use a hinging device incorporating two torsion bars extending between two hinges mounted on the vehicle and connected to one end of two straps. The other ends of the straps are connected to the closure panel or deck lid. The torsion bars counter-balance the weight of the deck lid and enable the deck lid to be more easily moved between raised and lower positions.
This hinge construction requires that the torsion bars and the strap hinges or pivot connections be assembled on the vehicle separately. Due to the location of the torsion bars below the rear shelf of the vehicle, installation and service of the torsion bars and the hinges is difficult and time consuming. Furthermore, two workers acting in concert are needed to attach the torsion bars between the two strap pivots or hinges which further adds to assembly time.
A deck lid hinge using torsion bars also creates packaging difficulties within the vehicle trunk since the torsion bars extend transversely across the trunk. The torsion bars take up space within the trunk and interfere with other vehicle components, such as the sound system speakers mounted on the parcel shelf. Further, torsion bars are noisy in operation, are sensitive to alignment, and do not perform particularly well due to high internal friction. As a result, the hinge counter-balance function is often times reduced to a brake which holds the deck lid open at any arbitrary position or is so powerful that it causes the deck lid to rise uncontrollably to its maximum opening position where it slams into stops, vibrating the entire vehicle and can even deform the sheet metal of the vehicle. The torsion bar hinge assembly is costly in terms of the number of separate components required for its assembly and its lengthy installation time. Further, the torsion bars are heavy which is a disadvantage in view of the desirability of reducing weight in current vehicles for increased fuel economy.
In order to increase available trunk space, the space below the parcel shelf where the torsion bars are typically mounted is being further limited. Finally, deck lids are becoming increasingly heavier due to added tail lamp assemblies, trunk and luggage racks, and spoilers thereby requiring higher counter-balance spring forces which results in larger and more costly torsion bars.
Other hinge arrangements have also been developed to overcome the above-described problems associated with the use of torsion bar hinge assemblies. In one such hinge assembly shown in FIG. 9 and used on a vehicle deck lid, a mounting plate 1 attached to a stationary vehicle structure, such as the rear parcel shelf, supports a clock spring 2 formed in a number of loops about a spring center 3 fixed to the mounting plate. A first link 4 is connected between the spring center 3 and the free end 5 of the spring 2 to retain the spring coil or loop at a constant radius during rotation of the free end 5 of the spring 2 as the deck lid is raised and lowered. At least one and, preferably, a pair of spaced drive links 6 are connected between the free end 5 of the spring 2 and a strap 7 which is pivotally connected at one end to the mounting plate 1 and fixed at another end to the vehicle deck lid. While this hinge assembly overcomes a large number of the problems associated with the use of torsion bar hinge assemblies used in automotive vehicles, this arrangement provides a fixed force versus spring position curve which limits the design of the hinge for different deck lid weights and different deck lid opening/closing profiles.
Thus, it would be desirable to provide a closure panel hinge which overcomes the aforementioned problems involved in closure panel hinges, particularly those employed for automotive vehicle closure panels. It would also be desirable to provide a closure panel hinge which can be advantageously employed as a vehicle deck lid hinge and which reduces hinge weight, space requirements and installation time as compared to previously-devised vehicle deck lid hinges. Finally, it would be desirable to provide a closure panel hinge which can be easily designed to provide any spring force versus closure panel position profile thereby adapting the hinge to a wide variety of different applications and different modes of operation.